Worldwide surveys indicate that the number of women studying undergraduate-level Computer Science is constantly decreasing. Based on data collected in Israel, significant differences were found in the percentages of female high school students studying advanced-level Computer Science among different sectors. More specifically, while the percentage of female high school students studying advanced-level Computer Science is about 50% for the Arab minority sector, the percentage of female students studying Computer Science at the same level among the Jewish majority sector is only about 25%. This situation was investigated by using both qualitative and quantitative research tools. The paper analyzes this situation within the model of "achievement-related choices" developed by Eccles and her colleagues. (Contains 15 tables.)